/*
 * The contents of this web application are subject to the Mozilla Public License Version 
 * 1.1 (the "License"); you may not use this web application except in compliance with 
 * the License. You may obtain a copy of the License at http://www.mozilla.org/MPL/.
 * 
 * Software distributed under the License is distributed on an "AS IS" basis, 
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
 * for the specific language governing rights and limitations under the License.
 * 
 * The Original Code is owned by and the Initial Developer of the Original Code is 
 * Composite A/S (Danish business reg.no. 21744409). All Rights Reserved
 * 
 * Section 11 of the License is EXPRESSLY amended to include a provision stating 
 * that any dispute, including but not limited to disputes related to the enforcement 
 * of the License, to which Composite A/S as owner of the Original Code, as Initial 
 * Developer or in any other role, becomes a part to shall be governed by Danish law 
 * and be initiated before the Copenhagen City Court ("K�benhavns Byret")            
 */

using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;


namespace Composite.Data.Foundation
{
    internal sealed class DataFacadeQueryableGathererExpressionVisitor : ExpressionVisitor
    {
        private List<IDataFacadeQueryable> _multibleSourceQueryables = new List<IDataFacadeQueryable>();
        private int _sourceCount = 0;

        protected override Expression VisitConstant(ConstantExpression c)
        {
            if (c.Value is IDataFacadeQueryable)
            {
                IDataFacadeQueryable multibleSourceQueryable = (IDataFacadeQueryable)c.Value;

                _sourceCount += multibleSourceQueryable.Sources.Count();

                IDataFacadeQueryable found = _multibleSourceQueryables.Find(delegate(IDataFacadeQueryable queryable) { return object.ReferenceEquals(multibleSourceQueryable, queryable); });

                if (found == null)
                {
                    _multibleSourceQueryables.Add(multibleSourceQueryable);
                }
            }

            return base.VisitConstant(c);
        }


        public List<IDataFacadeQueryable> MultibleSourceQueryables
        {
            get { return _multibleSourceQueryables; }
        }


        public int SourceCount
        {
            get { return _sourceCount; }
        }
    }
}
